Furfurylimino compounds

ABSTRACT

RCH2-N=CH-R&#39;&#39;   WHEREIN R IS 2-FURYL AND R&#39;&#39; IS A TERMINALLY BRANCHED ALKYL GROUP CONSISTING FROM 3 TO 6 CARBON ATOMS. 1. AN ALDIMINE OF THE FORMULA

United States Patent O U.S. Cl. 260347.7 Claims ABSTRACT OF THEDISCLOSURE Novel aldimines are useful as choclate-like or cocoa-likeflavors. Examples of the novel compounds areN-isobutylidenefurfurylamine, N-isopentylidenefurfurylamine, andN-isopentylideneisopentylamine.

CROSS REFERENCE TO RELATED APPLICATION This is a division of co-pendingapplication Ser. No. 836,606, filed June 25, 1969, and now U.S. Pat.3,625,710.

BACKGROUND OF THE INVENTION This invention relates to a new class ofchocolate like or cocoa-like flavors. The compounds of this class can beused per se to supplement, extend and fortify the flavor supplied tocakes, candy, puddings, beverages and the like by chocolate or cocoa.They can also be used as components in artificial flavor mixturessuitable for supplying chocolate or cocoa notes to food products.

SUMMARY OF THE INVENTION The compounds of this invention which have theabovedescribed utility are novel aldimines.

THE PRIOR ART Imines are generally known. In this regard, see R. W.Layer, Chem. Revs, 63, 489-5 (1963). Moreover, A- pyrroline, a cyclicimine, is disclosed in Nakel U.S. 3,336,- 138 as a food flavor additivewhich provides a crusty, potato-like or a buttery flavor. However, theparticular compounds of this invention are not known to be described inthe prior art. Nor is the fact that any imines have a chocolate-likeflavor known to be described in the prior art. In fact, Montgomery, M.W. and Day, E. A., J. Food Sci. 30, #5, 828-832 (1965) implies that theformation of imines in food products is detrimental to flavor.

Other prior art disclosing artificial chocolate flavors but not known todisclose the compounds of the present invention include U.S. Pats.2,835,590; 2,835,592593; and 2,887,384388.

DETAILED DESCRIPTION OF THE INVENTION The novel compounds herein havethe structural formula RCH -N=CH-R wherein either (1) R is a Z-furylgroup and R is a terminally branched alkyl group containing 3 to 6carbon atoms; or (2) R is an isobutyl group and R is also an isobutylgroup.

These compounds include N-isobutylidenefurfurylamine,N-isopentylidenefuriurylamine, N-isohexylidenefurfurylamine,N-isoheptylidenefurfurylamine, and N-isopentylideneisopentylamine.

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N-isobutylidenefurfurylamine has the above structural formula wherein Ris a 2-furyl group and R is a terminally branched alkyl group containing3 carbon atoms. N-isopentylidenefurfurylamine has the above structuralformula wherein R is a Z-furyl group and R is a terminally branchedalkyl group containing 4 carbon atoms. N-isohexylidenefurfurylamine hasthe above structural formula wherein R is a 2-furyl group and R is aterminally branched alkyl group containing 5 carbon atoms.N-isoheptylidenefurfurylamine has the above structural formula wherein Ris a Z-furyl group and R is a terminally branched alkyl group containing6 carbon atoms. N-isopentylideneisopentylamine has the above structuralformula wherein R is an isobutyl group and R is also an isobutyl group.

These compounds are conveniently prepared by reacting appropriatealdehydes and amines according to the following reaction equationwherein R and R have the definitions given above:

It is preferred that this reaction be carried out by adding thealdehydic component to the amine with external cooling. Optionally, aninert solvent such as ether can be added to moderate the reaction.

The 2-furyl substituted compounds of this invention can also be preparedby reacting furfural with an appropriate terminally branched alpha aminoacid. For example, N-isopentylidenefurfurylamine can be prepared byreacting furfural and L-leucine.

The novel compounds of this invention can be used to supplychocolate-like or cocoa-like notes to food prod ucts. They can be usedfor this purpose at levels ranging from 0.5 ppm. to 10,000 p.p.m., basedon the weight of the food product to which they are added. Preferably,these compounds are utilized at levels ranging from 1 ppm. to 2000 ppm,based on the weight of the food product to which they are added.

The novel compounds can be used in pure form or in combination with acarrier. Suitable carriers include water, ethanol, mineral oil,dextrose, starch, or gum arabic. When used in combination with a carrierto provide a amounts to from 1% to 10% by weight of the flavorcomposition.

The novel compounds of this invention can also be used in combinationwith other flavor components to provide artificial flavor mixturessuitable for supplying chocolate or cocoa notes to food products. Theseother flavor components include vanillin, ethyl vanillin, linalool,anisic aldehyde, and acetaldehyde. These other flavor components alsoinclude particular alkyl pyrazines. Suitable alkyl pyrazines aredisclosed in Nakel and Dirks, patent application Ser. No. 677,030 filedOct. 23, 1967, now U.S. Pat. 3,579,353. These other flavor componentsalso include particular Z-alkylthiazolidines. These thiazolidines aredescribed in my copending patent application Ser. No. 836, 607, now U.S.Pat. 3,617,310 entitled 2-Alkylthiazolidines as Chocolate-Like Flavorswhich was filed June 25, 1969.

The following Examples further illustrate the novel compounds herein,their preparation, their flavor properties, and their use in anartificial flavor mixture and in a food product to supply significantlyenhanced chocolate-like or cocoa-like flavor. Examples I-IV illustratethe novel compounds herein, their preparation, and their flavorproperties. Example V illustrates the use of novel compounds herein ascomponents in artificial flavor mixtures. Example VI illustrates the useof novel compounds herein to supply an enhanced cocoa-like orchocolate-like flavor to devils food cake.

3. EXAMPLE I Preparation of N-Iisobutylidenefurfurylamine Furfurylamine(19.4 grams, 0.20 mole) is treated dropwise with 17.7 milliliters (0.20mole) of isobutyraldehyde; the temperature of the reaction is maintainednear 25 C. with intermittent ice-cooling. After completion of theaddition (about 10 minutes), the mixture is stirred for 30 minutes at 25C. and treated with NaOH pellets to absorb water which forms in thereaction. Ordinary work up with ether followed by distillation yields16.3 grams of analytically pure N isobutylidenefurfurylamine boilingfrom 8283 C. under 11 millimeters Hg pressure. Analysis: Calculated forC H NO: C=71.2%, H=8.9%, N=9.3%; Found: O=71.5%; H=8.7% and N=9.5%.

Some of the above-formed N-isobutylidenefurfurylamine is admixed withmineral oil so as to be present in the combination at a level of 1p.p.m. by weight. The combination gives sweet chocolate aroma sensation.

The N-isobutylidenefurfurylamine sniflFed in water at a level of 1p.p.m. by weight gives a chocolate aroma sensation.

EXAMPLE II Preparation of N-Isopentylidenefurfurylamine Furfurylamine(15.57 grams, 0.15 mole) is treated dropwise with 16.1 milliliters (0.15mole) of isovaleraldehyde; the temperature of the reaction is maintainednear 25 C. with intermittent icecooling. After completion of theaddition (about 10 minutes), the mixture is stirred 30 minutes at 25 C.and treated with NaOH pellets to absorb water which forms in thereaction. Ordinary work up with ether yields 25.2 grams of crude productwhich on distillation gives 19.9 grams of analytically pureN-isopentylidenefurfurylamine (hereinafter referred to as IPFA) boilingfrom 9297 C. under 12 millimeters Hg pressure. Analysis: Calculated forC H NO:

H=9.15%, N=8.48%; Found: C=72.0%, H=9.4% and N=8.5%. The IPFA whensniffed at a level of 1 p.p.m. by Weight in either mineral oil or watergives a chocolate aroma sensation.

N-isohexylidenefurfurylamine is formed when an equivalent amount of4-methylpentanal is subsituted for the isovaleraldehyde above.N-isoheptylidenefurfurylamine is formed when an equivalent amount ofS-methylhexanal is substituted for the isovaleraldehylde above. Theseproducts when sniifed in mineral oil or water at a 1 p.p.m. by weightlevel give a chocolate aroma sensation.

EXAMPLE III Preparation of N-isopentylidenefurfurylamine A slurry ofL-leucine (13.8 grams, 0.15 mole) in 50 milliliters anhydrous diglyme istreated with 9.61 grams (0.10 mole) of redistilled furfural. The mixtureis stirred and refluxed under a nitrogen atmosphere for 2 hours. Theresulting reaction mixture having cooled is steam distilled and theaqueous distillate (500 milliliters) is saturated with solid NaCl andextracted With ether (3 times with 100 milliliters each time). Thecombined ether phase is back-extracted with water (5 times with 50milliliters each time), washed with saturated brine and dried overanhydrous MgSO Evaporation of the ether under reduced pressure gives13.7 grams of crude product. Distillation of the crude product gives1.73 grams of substantially pure N-isopentylidenefurfurylamine (IPFA).The IPFA when snified at a level of 1 p.p.m. by weight in either mineraloil or Water gives a chocolate aroma sensation.

EXAMPLE IV Preparation of N-Isopentylideneisopentylamine Isopentylamine(29.0 milliliters, 0.25 mole) is treated dropwise with 26.9 milliliters(0.25 mole) of isovaleraldehyde. The temperature of the reaction ismaintained near 25 C. with intermittent ice-cooling. Workup similar tothat described in Example I gives 35.2 grams of product having a boilingrange of 6668 C. at 12-13 millimeters Hg pressure. The product is shownto be substantially pure N-isopentylideneisopentylamine (IPPA) by thefollowing elemental analysis: Calculated for C H N: C=77.4%, H=13.6%,N=9.04%; Found: C=76.7%, H-=13.5%, and N=9.9%.

The IPPA when sniffed at a level of 1 p.p.m. by weight in water gives achocolate aroma sensation.

EXAMPLE V Artificial Chocolate Flavor Mixture An artificial chocolateflavor mixture is made up containing the following percentages ofingredients:

The above artificial chocolate flavor mixture when sniffed in water ormineral oil at a 2 p.p.m. by weight level gives a very rich chocolatearoma. This chocolate aroma is significantly richer than the aromasensation given by 1 p.p.m. N-isobutylidenefurfurylamine alone in Water.

Similar results of very rich chocolate aroma sensation are achieved whenequal weights of N-isopentylidenefurfurylamine orN-isopentylideneisopentylamine are substituted for theN-isobutylidenefurfurylamine in the above artificial chocolate flavormixture.

EXAMPLE VI Use of N-isopentylideneisopentylamine to enhance thechocolate-like or cocoa-like flavor of devils food cake A devils fooddry mix is prepared having the following composition:

Ingredient: Percent By Weight Flour (soft wheat cake flour including0.5%

by weight high-protein wheat flour) 38.18 Sugar (industrial finegranulated sucrose and dextrose) 39.30 Shortening 1 11.00 Sodiumbicarbonate 2.45 Sodium aluminum phosphate 0.70 Nonfat milk solids 1.00Carboxymethyl cellulose 0.20 Salt 1.00 Cocoa 6.00 Butter-like flavorBalance flhe shortening is prepared by melting together the followingand plasticlzing by rapidly cooling with agitation (percentages are byweight) vegetable oil shortening comprising about 80 7 so bean oil and20% cottonseed oil, which have beer re iined, bleached, deodorized andhydrogenated to an iodine value of about 60 14.0% alpha-phasecrystal-tending emulsifiers comprised of iltlygrigiopylene glycolmonostearate and 4% rapeseed 0.256273 haigltemperature batter stabilizercomprised of stearlc 5.75% propylene glycol distearate (an inertby-product from propylene glycol monostearate preparation).

The mix is prepared by blending together thoroughly the flour, sugar andshortening in a paddle mixer, and then passing the blend through aroller mill. After the milling step, the remaining ingredients areadded, and the resulting mixture is processed in an entoleter.

Batter is then made by adding three whole eggs and 1.33 cups of water to19 ounces of the mix. To this batter is added a dispersion ofN-isopentylideneisopentylamine (IPPA) in dextrose (5% by weight IPPA andthe re mainder dextrose) to provide in the batter 200 ppm. IPPA based onthe weight of the dry mix in the batter. The batter is then mixed in aconventional household electric mixer for 3 minutes at high speed (875r.p.m.) and for 1 minute at medium speed (450 r.p.m.). A nineinch cakepan is filled with 492 grams of batter and baked at 350 F. for 32minutes.

The resulting devils food cake has significantly more cocoa-like flavorthan devils food cake made the same but without the addition of theIPPA.

Similar results of significantly more cocoa-like flavor are achievedwhen cake is made as above except that IPPA-dextrose dispersion is addedto provide 500 p.p.m., 600 p.p.m., 1000 p.p.m. or 1500 p.p.m. IPPA byweight of the dry mix in the batter insead of 200 p.p.m.

Devils food cake is made the same as above except that instead of IPPA,N-isobutylidenefurfurylamine (IBFA) is added to the batter to provide inthe batter 200 p.p.m. IBFA based on the weight of the dry mix in thebatter. The resulting cake has significantly more milk chocolate flavorthan cake made the same but without addition of IBFA.

Silimar results of significant more milk chocolate are achieved whencake is made as in the above paragraph except that IBFA-dextrosedispersion is added to provide 500 p.p.m., 600 p.p.m., 1000 ppm, or 1500ppm. IBFA wherein R is 2-furyl and R is a terminally branched alkylgroup containing from 3 to 6 carbon atoms.

2. The aldimine of claim 1 wherein R is isopropyl.

3. The aldimine of claim 1 wherein R is a terminally branched alkylgroup having 4 carbon atoms.

4. The aldimine of claim 1 wherein R is a terminally branched alkylgroup having 5 carbon atoms.

5. The aldimine of claim 1 wherein R' is a terminally branched alkylgroup having 6 carbon atoms.

References Cited UNITED STATES PATENTS 2/1971 Bouniot 260347.7 X

OTHER REFERENCES Beilstein: Organische Chemie., Berlin (1922), Band 4,p. 189.

JOHN D. RANDOLPH, Primary Examiner B. DENTZ, Assistant Examiner

1. AN ALDIMINE OF THE FORMULA